Up to 75 full- and part-time editorial jobs are to be cut at Trinity Mirror's London-based national newspapers, the Daily Mirror, Sunday Mirror and People.

The company said on Wednesday the job cuts were necessary to "meet the economic challenges" and "the technological revolution facing the industry". The cuts could save millions of pounds a year in payroll alone.

Trinity Mirror did not rule out compulsory redundancies but said the aim was achieve the staff cuts through voluntary departures in as many cases as possible.

As part of the cost-cutting initiative, the company is making radical changes to reporting and production activities for the three titles, which currently have separate operations.

This involves a partial merging of the reporting and production operations across a seven-day rota.

However, Trinity Mirror said each paper will continue to have "a bespoke editorial team" to "protect their unique identity". The company also plans to increase the number of pages outsourced to the Press Association for subediting.

The Daily Mirror editor, Richard Wallace, will take on management responsibility for the merged "content and production hub" in addition to his current role.

"[The] restructuring proposals for its UK national titles which represent the next stage in its aim to create one of the most technologically advanced and operationally efficient multimedia newsrooms in Europe," Trinity Mirror said a statement.

The publisher added that the new operation will give editors greater "flexibility" and "increase the range and depth of regional coverage" with the recruitment of a number of district reporters.

The cuts mean the the company will have slashed its editorial staff on the three titles by nearly 40% in the last two years – in June 2010 it axed about 140 full times posts from 554 – and after the latest round of cuts the headcount will be down to about 340.

A spokesman said elements of the news reporting operation and specialist desks such as sport and showbusiness and other "specialist" editorial teams would be shared across the titles but the details had yet to be worked out.

Sly Bailey, who received a remuneration package of £1.7m in 2010, told the Leveson inquiry in January that "the pressures on the business over about the last five years have been intense" with the structural problem stemming from the increase in consumption of news of digital devices combining with the cyclical pressure brought by the recession. "My view is the cycle has been much worse for us than the structural issues," Bailey said.

She added that Trinity Mirror's regional titles had been hit worst by the recession with recruitment advertising in particular collapsing, closing 20 titles out of 160 between October and January. At the peak the company was taking £150m in job adverts but last year it only generated £20m.

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